// Copyright (c) 2004-2008 MySQL AB, 2008-2009 Sun Microsystems, Inc.
//
// MySQL Connector/NET is licensed under the terms of the GPLv2
// <http://www.gnu.org/licenses/old-licenses/gpl-2.0.html>, like most 
// MySQL Connectors. There are special exceptions to the terms and 
// conditions of the GPLv2 as it is applied to this software, see the 
// FLOSS License Exception
// <http://www.mysql.com/about/legal/licensing/foss-exception.html>.
//
// This program is free software; you can redistribute it and/or modify 
// it under the terms of the GNU General Public License as published 
// by the Free Software Foundation; version 2 of the License.
//
// This program is distributed in the hope that it will be useful, but 
// WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 
// or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 
// for more details.
//
// You should have received a copy of the GNU General Public License along 
// with this program; if not, write to the Free Software Foundation, Inc., 
// 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA

#if !PocketPC

using System.Data.Common;
using System;
using System.Reflection;
using System.Security.Permissions;
using System.Security;

namespace MySql.Data.MySqlClient
{
  /// <summary>
  /// DBProviderFactory implementation for MysqlClient.
  /// </summary>
  [ReflectionPermission(SecurityAction.Assert, MemberAccess = true)]  
  public sealed class MySqlClientFactory : DbProviderFactory, IServiceProvider
  {
    /// <summary>
    /// Gets an instance of the <see cref="MySqlClientFactory"/>. 
    /// This can be used to retrieve strongly typed data objects. 
    /// </summary>
    public static MySqlClientFactory Instance = new MySqlClientFactory();
    private Type dbServicesType;
    private FieldInfo mySqlDbProviderServicesInstance;

    /// <summary>
    /// Returns a strongly typed <see cref="DbCommandBuilder"/> instance. 
    /// </summary>
    /// <returns>A new strongly typed instance of <b>DbCommandBuilder</b>.</returns>
    public override DbCommandBuilder CreateCommandBuilder()
    {
      return new MySqlCommandBuilder();
    }

    /// <summary>
    /// Returns a strongly typed <see cref="DbCommand"/> instance. 
    /// </summary>
    /// <returns>A new strongly typed instance of <b>DbCommand</b>.</returns>
    public override DbCommand CreateCommand()
    {
      return new MySqlCommand();
    }

    /// <summary>
    /// Returns a strongly typed <see cref="DbConnection"/> instance. 
    /// </summary>
    /// <returns>A new strongly typed instance of <b>DbConnection</b>.</returns>
    public override DbConnection CreateConnection()
    {
      return new MySqlConnection();
    }

    /// <summary>
    /// Returns a strongly typed <see cref="DbDataAdapter"/> instance. 
    /// </summary>
    /// <returns>A new strongly typed instance of <b>DbDataAdapter</b>. </returns>
    public override DbDataAdapter CreateDataAdapter()
    {
      return new MySqlDataAdapter();
    }

    /// <summary>
    /// Returns a strongly typed <see cref="DbParameter"/> instance. 
    /// </summary>
    /// <returns>A new strongly typed instance of <b>DbParameter</b>.</returns>
    public override DbParameter CreateParameter()
    {
      return new MySqlParameter();
    }

    /// <summary>
    /// Returns a strongly typed <see cref="DbConnectionStringBuilder"/> instance. 
    /// </summary>
    /// <returns>A new strongly typed instance of <b>DbConnectionStringBuilder</b>.</returns>
    public override DbConnectionStringBuilder CreateConnectionStringBuilder()
    {
      return new MySqlConnectionStringBuilder();
    }

    /// <summary>
    /// Returns true if a <b>MySqlDataSourceEnumerator</b> can be created; 
    /// otherwise false. 
    /// </summary>
    public override bool CanCreateDataSourceEnumerator
    {
      get { return false; }
    }

    #region IServiceProvider Members

    /// <summary>
    /// Provide a simple caching layer
    /// </summary>
    private Type DbServicesType
    {
      get
      {
        if (dbServicesType == null)
        {
          // Get the type this way so we don't have to reference System.Data.Entity
          // from our core provider
          dbServicesType = Type.GetType(
              @"System.Data.Common.DbProviderServices, System.Data.Entity, 
                        Version=3.5.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089",
                                                                                false);
        }
        return dbServicesType;
      }
    }

    private FieldInfo MySqlDbProviderServicesInstance
    {
      get
      {
        if (mySqlDbProviderServicesInstance == null)
        {
          string fullName = Assembly.GetExecutingAssembly().FullName;
          string assemblyName = fullName.Replace("MySql.Data", "MySql.Data.Entity");
          string assemblyEf5Name = fullName.Replace("MySql.Data", "MySql.Data.Entity.EF5");
          fullName = String.Format("MySql.Data.MySqlClient.MySqlProviderServices, {0}", assemblyEf5Name);

          Type providerServicesType = Type.GetType(fullName, false);
          if (providerServicesType == null)
          {
            fullName = String.Format("MySql.Data.MySqlClient.MySqlProviderServices, {0}", assemblyName);
            providerServicesType = Type.GetType(fullName, false);
            if (providerServicesType == null)
              throw new DllNotFoundException(fullName);
          }
          mySqlDbProviderServicesInstance = providerServicesType.GetField("Instance",
              BindingFlags.NonPublic | BindingFlags.Static | BindingFlags.Instance);
        }
        return mySqlDbProviderServicesInstance;
      }
    }

    object IServiceProvider.GetService(Type serviceType)
    {
      // DbProviderServices is the only service we offer up right now
      if (serviceType != DbServicesType) return null;

      if (MySqlDbProviderServicesInstance == null) return null;

      return MySqlDbProviderServicesInstance.GetValue(null);
    }

    #endregion
  }
}

#endif
